A father's age at the birth of his daughter may affect her later cancer risk, City of Hope researchers have found.

Newswise — Paternal age and the health effects it has on potential offspring have been the focus of many studies, but few have examined the effect parental age has on the risk of adult-onset hormone-related cancers (breast cancer, ovarian cancer and endometrial cancer).

A team of City of Hope researchers, lead by Yani Lu, Ph.D., explored this relationship and found that a parent’s age at birth, particularly a father’s age, may affect the adult-onset cancer risk for daughters — especially for breast cancer.

“Our findings indicate that parental age, especially paternal age, at conception appears to be associated with a wide range of effects on the health and development of the offspring,” Lu said.

To help determine the effects of parental age on the risk of adult-onset hormone-related cancers, Lu and her colleagues examined a cohort of 133,479 female teachers and administrators from the California Teachers Study. Between 1995 and 2010, 5,359 women were diagnosed with breast cancer, 515 women were diagnosed with ovarian cancer and 1,110 women were diagnosed with endometrial cancer.

While the team of researchers did not find an association for maternal age at birth for any type of cancer, they found that paternal age is linked to an increased adult-onset cancer risk for daughters – and the link was not only to advanced paternal age.

Women born to a father under the age of 20 had a 35 percent greater risk of breast cancer and more than two times greater risk of ovarian cancer, when compared to those born to a father whose age at his daughter’s birth was 25 to 29 years old.

Women born to a father whose age at childbirth was 30 to 34 years had a 25 percent greater risk of endometrial cancer than those born to a father age 25 to 29.

Lu and her team were not surprised to find a relationship between older fathers and an increased risk of hormone-related cancers, especially since there has been increasing evidence suggesting that daughters born to older fathers have increased risk of breast cancer, noted Lu.

However, there have been no previous studies that examine the effects that young paternal age has on a daughter’s breast cancer risk or the effects of parental age on the risk of ovarian cancer and endometrial cancer.

“We observed that young paternal age, as well as advanced paternal age, increase the risk of breast cancer,” said Lu. “We also found that young paternal age increases the risk of ovarian cancer.”

Lu and her colleagues will present these findings Monday during a poster session at the American Association for Cancer Research’s annual meeting in San Diego, held April 5 to 9.

Other experts involved in this study included City of Hope’s Jianning Luo, biostatistician I, Sophia Wang, Ph.D., associate professor, Huiyan Ma, Ph.D., assistant research professor, Jane Sullivan-Halley, clinical research administrator, and Leslie Bernstein, Ph.D., professor and director of cancer etiology. It also included Peggy Reynolds, Ph.D., M.P.H., from Cancer Prevention Institute of California in Berkeley, Calif.

Research reported in this publication was supported by the National Institutes of Health under the R03 CA162140 grant. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.